1. Field of the Invention
It applies more particularly to a smart card.
The invention also relates to an embedded system for implementing the method.
In the context of the invention, the term “embedded system” refers to various systems or devices having in common the fact of using a microchip comprising data storage and data processing means, generally constituted by a microprocessor or a microcontroller. Such an embedded system can be constituted, in particular, by a smart card.
The term “sensitive” should be understood in its most general sense. It concerns all sorts of secret or at least confidential data, including encryption algorithms, secret encryption keys, identification data or information of a secret nature, etc., stored in one or more types of memories with which the smart cards are equipped. This type of data will hereinafter be referred to generically as “secret.”
The invention applies more particularly, though not exclusively, to the storage of secret keys stored in order to be used for the secure pre-initialization of smart cards. In fact, it is well known that functions related to security are devolved to smart cards. Here again, the term security should be understood in a broad sense. This term actually covers various concepts: confidentiality, authentication, etc.
Hereinafter, in order to illustrate the concepts without in any limiting its scope, we will consider the preferred application of the invention, unless otherwise mentioned.
2. Description of the Related Art
Normally, in the prior art, the secrets contained in smart cards are stored linearly in the same storage area. In particular, the secrets are stored in permanent read-only memories (“ROM”) or semi-permanent, i.e. electrically erasable programmable read-only memories, for example of the “EEPROM” type. The memories of microchips are vulnerable to hackers, and the attacks seen are becoming increasingly numerous and sophisticated.
In particular, the “dumping” (or copying) of the “ROM” memory is a constant concern for smart cards.
Memories of the “EEPROM” type, which traditionally contain so-called sensitive data, are subject to most of the attacks known at the present time.